TWI742353B - Inspection apparatus, lithographic apparatus for measuring micro-diffraction-based overlay, and method for measuring micro-diffraction-based overlay - Google Patents

Abstract

An inspection apparatus or lithographic apparatus includes an optical system and a detector. The optical system includes a non-linear prismatic optic. The optical system is configured to receive zeroth and first diffraction order beams reflected from a diffraction target and separate first and second polarizations of each diffraction order beam. The detector is configured to simultaneously detect first and second polarizations of each of the zeroth and first diffraction order beams. Based on the detected first and second polarizations of one or more diffraction orders, an operational parameter of a lithographic apparatus can be adjusted to improve accuracy or precision in the lithographic apparatus. The optical system can include a plurality of non-linear prismatic optics. For example, the optical system can include a plurality of Wollaston prisms.

Description

Detection device, lithography device for measuring superposition based on micro-diffraction, and method for measuring superimposed pair based on micro-diffraction

The present invention relates to an optical system for detection devices, such as detection devices used in lithography devices and systems.

A lithography device is a machine that applies a desired pattern to a substrate (usually applied to a target portion of the substrate). The lithography device can be used in, for example, integrated circuit (IC) manufacturing. In that case, a patterned device (which is alternatively referred to as a photomask or a reduction photomask) can be used to produce circuit patterns to be formed on individual layers of the IC. This pattern can be transferred to a target part (for example, a part containing a die, a die, or a plurality of dies) on a substrate (such as a silicon wafer). The pattern transfer is usually performed by imaging onto a layer of radiation sensitive material (resist) provided on the substrate. Generally speaking, a single substrate will contain a network of adjacent target portions that are sequentially patterned. Known photolithography devices include: so-called steppers, in which each target part is irradiated by exposing the entire pattern onto the target part at one time; and so-called scanners, in which by moving in a given direction ("scanning ”Direction) through the radiation beam scanning pattern at the same time parallel or anti-parallel to the scanning direction and synchronously scan the target part to irradiate each target part. It is also possible to transfer the pattern from the patterned device to the substrate by embossing the pattern onto the substrate.

In order to monitor the lithography process, the parameters of the patterned substrate are measured. For example, the parameters may include the stacking error between successive layers formed in or on the patterned substrate, and Critical line width of developed photosensitive resist. This measurement can be performed on the product substrate and/or on a dedicated measurement target. There are various techniques for measuring the microstructure formed in the lithography process, including the use of scanning electron microscopes and various specialized tools. A fast and non-invasive form of a specialized inspection tool is a scatterometer, in which the radiation beam is directed to a target on the surface of the substrate, and the properties of the scattered beam or the reflected beam are measured. By comparing the properties of the light beam before and after it has been reflected or scattered by the substrate, the properties of the substrate can be determined. For example, this determination can be made by comparing the reflected beam with data stored in a known measurement library associated with known substrate properties. The spectral scatterometer directs the broad-band radiation beam onto the substrate and measures the spectrum (intensity that varies depending on the wavelength) of the radiation scattered into a specific narrow angle range. In contrast, an angle resolved scatterometer uses a monochromatic beam of radiation and measures the intensity of scattered radiation that changes depending on the angle.

Such optical scatterometers can be used to measure parameters, such as the critical dimension of the resulting photoresist or overlay error (OV) between two layers formed in or on the patterned substrate. By comparing the properties of the illumination beam before and after it has been reflected or scattered by the substrate, the properties of the substrate can be determined.

As semiconductor devices become smaller and more sophisticated, manufacturing tolerances continue to become stricter. Therefore, there is a need to continuously improve metrics. An exemplary use of the scatterometer is for critical dimension (CD) metrology, which is particularly suitable for measurement in patterned structures such as semiconductor wafers. Optical CD metrology technologies include dome scattering measurement, spectral reflectance measurement and spectral ellipsometry. All of these technologies are based on measuring the reflected intensity of light of different polarizations in different incident directions. This type of technology requires a high extinction ratio, or polarization purity. The polarization beam splitter (PBS) divides the light according to the polarization state to transmit the p-polarized light while reflecting the s-polarized light. Although a perfect PBS transmits 100% of p-polarization and reflects 100% of s-polarization, real PBS transmits and reflects a mixture of s-polarized light and p-polarized light. P-polarized light and The ratio between s-polarized light is called the extinction ratio. Optical CD requires a high extinction ratio.

Another exemplary use of the scatterometer is in Overlay (OV) metrology, which is used to measure the alignment of layer stacks on a wafer. In order to control the lithography process to accurately place the device features on the substrate, alignment marks or targets are usually provided on the substrate, and the lithography device includes one or more alignment systems, and the one or more The alignment system accurately measures the position of the mark on the substrate. In a known technique, scatter metrology measures the diffracted light from a target on the wafer. Use the "dark field" scattering measurement based on the diffraction-based stack to block zero-order diffraction (corresponding to specular reflection), and only process one or more high-order diffractions to generate a gray-scale image of the target. The diffraction-based overlay using this dark-field technology can achieve overlay measurement of smaller targets, and is called micro-diffraction based overlay (μDBO). However, μDBO may require extremely high contrast ratios.

Each product and process needs to be cautious in the design of weights and measures objectives and the selection of appropriate weights and measures "formulations" through which the overlap measurement will be performed. Some metrology techniques capture the diffraction pattern and/or dark field image of the metrology object when the object is illuminated under the desired lighting conditions. In the metrology formula, these lighting conditions are defined by various lighting parameters, such as the wavelength of radiation, angular intensity distribution (illumination profile), and polarization.

In some embodiments, a detection device includes an optical system and a detector. In some embodiments, the optical system includes a non-linear prismatic optical element. In some embodiments, the optical system is configured to receive zero and one diffraction order beams reflected from a diffraction target. In some embodiments, the optical system is configured to separate the first and second polarizations of each diffraction order beam. In some embodiments, the detector is configured to simultaneously detect the first and second polarizations of each of the zero and one diffraction order beams.

In some embodiments, the optical system is at a pupil plane of the detection device. In some embodiments, the nonlinear prismatic optical element is birefringent. In some embodiments, the nonlinear prismatic optical element is configured to separate normal rays and abnormal rays from each of the zero and one diffraction order beams. In some embodiments, the first polarization of each of the zero and one diffraction order beams is a horizontal polarization component, and the second polarization of each of the zero and one diffraction order beams The polarization is a vertical polarization component, which is orthogonal to the horizontal polarization component.

In some embodiments, the optical system further includes a plurality of nonlinear prismatic optical elements. In some embodiments, the plurality of nonlinear prismatic optical elements include a plurality of Wollaston horns. In some embodiments, the plurality of Wollaston rods includes a first type and a second type. In some embodiments, the plurality of Wollaston horns includes two Wollaston horns of the first type, each having a first wedge angle and a corresponding first divergence angle. For example, the first wedge angle and the corresponding first divergence angle may be 45°. In some embodiments, the plurality of Wollaston rods includes two Wollaston rods of the second type, each of which has a second wedge angle and a corresponding second divergence angle. For example, the second wedge angle and the corresponding second divergence angle may be 15°. In some embodiments, the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle. In some embodiments, the two first-type Wollaston rods are rotated 90° with respect to each other. In some embodiments, the two second-type Wollaston rods are rotated 90° with respect to each other.

In some embodiments, a lithography device for measuring micro-diffraction-based stacking includes a first illumination optical system, a projection optical system, and a scatterometer. In some embodiments, the first illumination optical system is configured to illuminate a diffraction pattern. In some embodiments, the projection optical system is configured to project an image of the diffraction pattern onto a substrate. In some embodiments, the scatterometer is configured to determine a parameter of the lithography device.

In some embodiments, the scatterometer includes a second illumination optical system, an objective optical system, and a detection device. In some embodiments, the second illumination optical system is configured to deliver at least one radiation beam. In some embodiments, the objective optical system is configured to focus the at least one radiation beam onto the substrate. In some embodiments, the detection device is configured to detect a reflected radiation beam from one of the substrates.

In some embodiments, the detection device of the scatterometer includes an optical system and a detector. In some embodiments, the optical system includes a non-linear prismatic optical element. In some embodiments, the optical system is configured to receive zero and one diffraction order beams reflected from a diffraction target and separate the first and second polarizations of each diffraction order beam. In some embodiments, the detector is configured to simultaneously detect the first and second polarizations of each of the zero and one diffraction order beams.

In some embodiments, the nonlinear prismatic optical element is a birefringent optical element, a Wollaston prism, a Nomarski prism, a Sénarmont prism, a Luo Hungarian (Rochon) prism, a Glam-Thompson prism, or a Glan-Foucault prism. In some embodiments, the optical system includes a neutral density filter. In some embodiments, the neutral density filter is configured to normalize an intensity of a zero diffraction order with respect to an intensity of a diffraction order. In some embodiments, the optical system is at a pupil plane of the detection device, and the detector is a single dark field detector. In some embodiments, the first polarization of each of the zero and one diffraction order beams is a horizontal polarization component, and the second polarization of each of the zero and one diffraction order beams The polarization is a vertical polarization component, which is orthogonal to the horizontal polarization component.

In some embodiments, the optical system further includes a plurality of nonlinear prismatic optical elements. In some embodiments, the plurality of nonlinear prismatic optical elements includes a plurality of Wollaston wins. In some embodiments, the plurality of Wollaston rods includes a first type and a second type.

In some embodiments, the plurality of Wollaston horns includes two Wollaston horns of the first type, each having a first wedge angle and a corresponding first divergence angle. For example, the first wedge angle and the corresponding first divergence angle may be 45°. In some embodiments, the plurality of Wollaston rods includes two Wollaston rods of the second type, each of which has a second wedge angle and a corresponding second divergence angle. For example, the second wedge angle and the corresponding second divergence angle may be 15°. In some embodiments, the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle. In some embodiments, the two first-type Wollaston rods are rotated 90° with respect to each other. In some embodiments, the two second-type Wollaston rods are rotated 90° with respect to each other.

In some embodiments, the plurality of Wollaston horns are arranged on a transparent plate in a 2×2 matrix array. In some embodiments, the plurality of Wollaston beams are configured to separately receive the first and second zero diffraction order sub-beams and the first and second first diffraction order sub-beams.

In some embodiments, a horizontal polarization component for each of the first and second zero-diffraction-order sub-beams and the first and second-diffraction-order sub-beams is orthogonal to the level One of the polarization components, the vertical polarization component, is separated by the corresponding plurality of Wollaston horns. In some embodiments, the horizontal polarization component and one vertical polarization component of each sub-beam are imaged by the detector into eight discrete beam spots.

In some embodiments, a method for measuring micro-diffraction-based overlays includes: zero and one-diffraction reflections from a diffractive target by an optical system including a nonlinear prismatic optical element The first and second polarizations of the second order beams are separated. In some embodiments, the method includes simultaneously detecting zero and one diffraction order and the first and first diffraction order of each diffraction order by a detector. The second polarization. In some embodiments, the method includes adjusting a parameter of interest of the diffractive target to improve the accuracy or precision in a metrology or lithography system. In some embodiments, the method includes adjusting or optimizing a parameter of a lithography device based on the detected first and second polarizations of one or more diffraction orders to improve the performance of the lithography device Accuracy, precision, timing, efficiency and/or productivity. In some embodiments, the method includes adjusting an operating parameter of a lithography device based on the detected first and second polarizations of one or more diffraction orders to improve the accuracy of the lithography device Or precision.

In some embodiments, the method includes separately separating the first and second zero-diffraction order sub-beams and the first and second first-diffraction order sub-beams. In some embodiments, the method includes isolating a horizontal polarization component and a positive polarization component for each of the first and second zero-diffraction-order sub-beams and the first and second diffraction-order sub-beams. Intersect one of the vertical polarization components of the horizontal polarization component. In some embodiments, the method includes imaging the horizontal and vertical polarization components of each zero and one diffraction order sub-beam into eight discrete beam spots on a single dark field detector.

Hereinafter, additional features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention are described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Based on the teachings contained herein, additional embodiments will be obvious to those familiar with the related art.

1: Connect the objective optical system

2: Broadband radiation projector/radiation source

4: Spectrometer detector

10: Spectrum

11: Back-projection pupil plane

12: Lens system

13: filter

14: reflector/reference mirror

15: Lens system/microscope objective lens system

16: Partially reflective surface/beam splitter

17: Polarizer

18: Detector

30: substrate target

100: Lithography device

100': Lithography device

210: EUV radiation emission plasma/extreme thermal plasma/

211: Source Chamber

212: Collector Chamber

219: open

220: enclosure structure

221: Radiation beam

222: Faceted Field Mirror Device

224: Faceted pupil mirror device

226: Patterned beam

228: reflective element

230: Use gas barrier or pollutant trap/pollution trap/pollutant barrier/reflective element

240: grating spectral filter

251: Upstream radiation collector side

252: Downstream radiation collector side

253: Grazing Incidence Reflector

254: Grazing incidence reflector

255: Grazing incidence reflector

300: Lithography Manufacturing Unit

600: Optical system

617a: zero diffraction order beam

617b: a diffraction order beam

623a: first polarization zero-order sub-beam/linear horizontal (H) polarization component

623b: First polarization first-order sub-beam/linear horizontal (H) polarization component

629a: second polarization zero-order sub-beam

629b: Second polarization first-order sub-beam

700: detection device

702: First (-0) zero-order sub-beam/first (-0) zero-order input sub-beam/zero-order diffracted beam

704: second (+0) zero-order sub-beam/second (+0) zero-order input sub-beam/zero-order diffracted beam

706: First (-1) first-order sub-beam/first (-1) first-order input sub-beam/first-order diffracted beam

708: second (+1) first-order sub-beam/second (+1) first-order input sub-beam/first-order diffracted beam

710: The first nonlinear prismatic optics

711: wedge connection

712: The first right-angled triangle orthogonal 鏡

713: Wedge Angle

714: Second Right Triangle Orthogonal 鏡

715a: Divergence angle

715b: Divergence angle

716a: the first (-0) zero-order output sub-beam of the first polarization/linear horizontal (H) polarization component

716b: The first (-0) zero-order output sub-beam of the second polarization

718a: The second (+0) zero-order output sub-beam of the first polarization/linear horizontal (H) polarization component

718b: The second (+0) zero-order output sub-beam of the second polarization

720: Second nonlinear prismatic optics

721: wedge connection

723: Wedge Angle

724: The second right-angled triangle orthogonal 鏡

725a: divergence angle

725b: divergence angle

726a: the first (-1) first-order output sub-beam of the first polarization/linear horizontal (H) polarization component

726b: The first (-1) first-order output sub-beam of the second polarization

728a: the second (+1) first-order output sub-beam of the first polarization/linear horizontal (H) polarization component

728b: The second (+1) first-order output sub-beam of the second polarization

730: lens system

740: Detector

750: optical system

800: optical system

802: 2×2 matrix array

804: transparent board

810: The first nonlinear prismatic optics / the first Wollaston prism

812: The first right-angled triangle orthogonal 鏡

814: The second right-angled triangle orthogonal 稜鏡

816: First (-0) zero-order sub-beam/input sub-beam

820: Second nonlinear prismatic optics/Second Wollaston prism

822: The first right-angled triangle orthogonal 鏡

823: wedge connection

824: The second right-angled triangle orthogonal 稜鏡

825: Wedge Angle

826: The second (+0) zero-order sub-beam

827: Divergence Angle

828a: Output sub-beam / second (+0) zero-order sub-beam of the first polarization / linear horizontal (H) polarization component

828b: Output sub-beam/second (+0) zero-order sub-beam of the second polarization/linear vertical (V) polarization component

830: The third nonlinear prismatic optics/the third Wollaston prism

832: The first right-angled triangle orthogonal 鏡

833: wedge connection

834: Second Right Triangle Orthogonal Neck

835: Wedge Angle

836: The first (-1) first-order sub-beam

838a: Output sub-beam/first (-1) first-order sub-beam of the first polarization/linear horizontal (H) polarization component

838b: Output sub-beam/first (-1) first-order sub-beam of the second polarization/linear vertical (V) polarization component

840: Fourth nonlinear prismatic optics/Fourth Wollaston prism

842: The first right-angled triangle orthogonal 鏡

844: Second Right Triangle Orthogonal 鏡

845: Wedge Angle

846: Second (+1) first-order sub-beam

847: Divergence Angle

848a: Output sub-beam / second (+1) first-order sub-beam of the first polarization / linear level (H) Polarization component

848b: Output sub-beam/second (+1) first-order sub-beam of the second polarization/linear vertical (V) polarization component

900: Optical system

902: 2×2 matrix array

904: transparent board

910: The First Wollaston Cube

920: The Second Wollaston Mirror

930: The Third Wollaston Cube

940: The Fourth Wollaston Cube

1000: Optical system

1002: Upper diagonal area/horizontal (H) polarization component

1004: Lower diagonal area / vertical (V) polarization component

1006: Detector

1018a: The first (-0) zero-order sub-beam of the first polarization

1018b: The first (-0) zero-order sub-beam of the second polarization

1028a: The second (+0) zero-order sub-beam of the first polarization

1028b: The second (+0) zero-order sub-beam of the second polarization

1038a: The first (-1) first-order sub-beam of the first polarization

1038b: The first (-1) first-order sub-beam of the second polarization

1048a: The second (+1) first-order sub-beam of the first polarization

1048b: The second (+1) first-order sub-beam of the second polarization

AD: adjuster

B: Radiation beam

BD: beam delivery system

BK: Baking board

C: target part

CH: cooling plate

CO: condenser/radiation collector/collector optics

DE: Developer

F: Focal length

IA: detection device

IF: position sensor/virtual source point/intermediate focus

IF1: position sensor

IF2: position sensor

IL: Illumination system/illuminator/illumination optics unit

IN: Accumulator

I/O1: input/output port

I/O2: input/output port

IPU: Illumination system pupil

IVR: Robot in vacuum

L1: Upper lens or upper lens group

L2: Lower lens or lower lens group

LACU: Lithography Control Unit

LB: loading box

M1: Mask alignment mark

M2: Mask alignment mark

MA: patterned device/mask

MP: mask pattern/mark pattern/line pattern

MP': video

MT: support structure/mask table

ND: Neutral Density Filter

O: Optical axis

P1: substrate alignment mark

P2: substrate alignment mark

PD: Aperture device

PM: the first locator

PPU: Conjugate pupil

PS: Projection system

PU: Processing Unit

PW: second locator

RO: substrate handler or robot

SC: Spin coater

SCS: Supervisory Control System

SM1: Scatterometer

SM2: Scatterometer

SO: Pulsed radiation source/source collector device

TCU: Coating and developing system control unit

V: vacuum chamber

W: substrate

WT: substrate table

The accompanying drawings incorporated herein and forming a part of this specification illustrate the present invention, and together with the description are further used to explain the principles of the present invention and enable those familiar with related art to make and use the present invention.

FIG. 1A is a schematic illustration of a reflection lithography apparatus according to an exemplary embodiment.

FIG. 1B is a schematic illustration of a transmission lithography apparatus according to an exemplary embodiment.

FIG. 2 is a more detailed schematic illustration of a reflection lithography apparatus according to an exemplary embodiment.

Fig. 3 is a schematic illustration of a lithography manufacturing unit according to an exemplary embodiment.

4 and 5 are schematic illustrations of scatterometers according to various exemplary embodiments.

Fig. 6 is a schematic illustration of an optical system used in a detection device according to an exemplary embodiment.

FIG. 7 is a schematic illustration of an exemplary optical system used in a detection device according to an exemplary embodiment.

Fig. 8 is a schematic illustration of an optical system according to an exemplary embodiment.

Fig. 9 is a schematic illustration of an optical system according to an exemplary embodiment.

Fig. 10 is a schematic illustration of an optical system according to an exemplary embodiment.

The features and advantages of the present invention will become more obvious based on the detailed description set forth below in conjunction with the drawings. In the drawings, similar component symbols always identify corresponding components. In the drawings, similar element symbols generally indicate elements that are the same, similar in function, and/or similar in structure. In addition, usually, the leftmost digit of a component symbol identifies the pattern in which the component symbol appears for the first time. Unless otherwise indicated, the drawings provided throughout the present invention should not be interpreted as drawings to scale.

This specification discloses one or more embodiments that incorporate the features of the present invention. Revealed The illustrated embodiments merely illustrate the present invention. The scope of the present invention is not limited to the disclosed embodiments. The present invention is defined by the scope of the patent application appended here.

The described embodiments and references in this specification to "an embodiment", "an embodiment", "an example embodiment", etc. The described embodiment may include a specific feature, structure, or characteristic, but each An embodiment may not necessarily include the specific feature, structure, or characteristic. In addition, these phrases do not necessarily refer to the same embodiment. In addition, when describing a particular feature, structure, or characteristic in conjunction with an embodiment, it should be understood that whether it is explicitly described or not, it is within the knowledge of those skilled in the art to realize this feature, structure, or characteristic in combination with other embodiments. .

For ease of description, spatial relative terms, such as "below", "below", "lower", "above", "above", "upper" and the like , Can be used herein to describe the relationship between one element or feature and another or more elements or features illustrated in the figures. In addition to the orientations depicted in the figures, spatially relative terms are also intended to cover different orientations of devices in use or operation. The device can be oriented in other ways (rotated by 90 degrees or in other orientations) and the spatial relative descriptors used herein can also be interpreted accordingly.

The term "about" as used herein indicates the value of a given quantity that can vary based on a particular technology. Based on a specific technology, the term "about" may indicate a value of a given quantity, which varies, for example, within 10% to 30% of the value (for example, ±10%, ±20%, or ±30% of the value).

The embodiments of the present invention can be implemented in hardware, firmware, software, or any combination thereof. The embodiments of the present invention can also be implemented as instructions stored on a machine-readable medium, and these instructions can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (eg, a computing device). For example, machine-readable media may include read-only memory (ROM); random access memory (RAM); Disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic or other forms of propagation signals (such as carrier waves, infrared signals, digital signals, etc.), and others. In addition, firmware, software, routines, and/or commands may be described herein as performing certain actions. However, it should be understood that such descriptions are only for convenience, and such actions are actually caused by computing devices, processors, controllers, or other devices that execute firmware, software, routines, commands, and so on.

However, before describing such embodiments in more detail, it is instructive to present an example environment in which embodiments of the present invention can be implemented.

Example lithography system

FIG. 1A and FIG. 1B are respectively schematic illustrations of a lithography device 100 and a lithography device 100' that can be used to implement embodiments of the present invention. The lithography device 100 and the lithography device 100' each include the following: an illumination system (illuminator) IL, which is configured to adjust the radiation beam B (for example, deep ultraviolet or extreme ultraviolet radiation); a support structure (for example, light Mask stage) MT, which is configured to support a patterned device (for example, a photomask, a reduction mask, or a dynamic patterned device) MA and is connected to a first position configured to accurately position the patterned device MA器PM; and the substrate table (eg, wafer table) WT, which is configured to hold the substrate (eg, resist coated wafer) W and connected to the second configured to accurately position the substrate W Locator PW. The lithography devices 100 and 100' also have a projection system PS configured to project the pattern imparted to the radiation beam B by the patterning device MA onto a target portion of the substrate W (for example, including one or more dies) C on. In the lithography apparatus 100, the patterned device MA and the projection system PS are reflective. In the lithography apparatus 100', the patterned device MA and the projection system PS are transmissive.

The illumination system IL may include various types of optical components for guiding, shaping or controlling the radiation beam B, such as refraction, reflection, catadioptric, magnetic, electromagnetic, electrostatic or Other types of optical components, or any combination thereof.

The support structure MT depends on the orientation of the patterned device MA relative to the reference frame, the design of at least one of the lithography apparatus 100 and 100', and other conditions (such as whether the patterned device MA is held in a vacuum environment) Way to hold the patterned device MA. The support structure MT may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterned device MA. The support structure MT can be, for example, a frame or a table, which can be fixed or movable as required. By using the sensor, the support structure MT can ensure that the patterned device MA (for example) is in a desired position relative to the projection system PS.

The term "patterned device" MA should be broadly interpreted as referring to any device that can be used to impart a pattern to the radiation beam B in its cross-section so as to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in the device produced in the target portion C in order to form an integrated circuit.

The patterned device MA may be transmissive (as in the lithography device 100' of FIG. 1B) or reflective (as in the lithography device 100 of FIG. 1A). Examples of patterned devices MA include shrinking masks, masks, programmable mirror arrays, and programmable LCD panels. Photomasks are well-known to us in lithography, and include mask types such as binary, alternating phase shift, and attenuated phase shift, as well as various hybrid mask types. An example of a programmable mirror array uses a matrix configuration of small mirrors, each of which can be individually tilted to reflect incident radiation beams in different directions. The tilted mirrors impart a pattern in the radiation beam B reflected by the matrix of small mirrors.

The term "projection system" PS can cover any type of projection system suitable for the exposure radiation used or other factors such as the use of immersion liquid on the substrate W or the use of vacuum, including refraction, reflection, catadioptric, Magnetic, electromagnetic and electrostatic optical systems, or any combination thereof. Vacuum environment can be used for EUV or electron beam radiation, this is because other gases can be Absorb too much radiation or electrons. Therefore, the vacuum environment can be provided to the entire beam path by virtue of the vacuum wall and the vacuum pump.

The lithography device 100 and/or the lithography device 100' may belong to a type having two (dual stage) or more than two substrate tables WT (and/or two or more mask tables). In such a "multi-stage" machine, additional substrate tables WT can be used in parallel, or preliminary steps can be performed on one or more tables while one or more other substrate tables WT are used for exposure. In some cases, the additional table may not be the substrate table WT.

The lithography device may also belong to the following type: at least a part of the substrate can be covered by a liquid (such as water) having a relatively high refractive index, so as to fill the space between the projection system and the substrate. The immersion liquid can also be applied to other spaces in the lithography device, such as the space between the mask and the projection system. The immersion technique is well known in the art for increasing the numerical aperture of projection systems. The term "wetting" as used herein does not mean that the structure such as the substrate must be submerged in liquid, but only means that the liquid is located between the projection system and the substrate during exposure.

1A and 1B, the illuminator IL receives the radiation beam from the radiation source SO. For example, when the source SO is an excimer laser, the source SO and the lithography device 100, 100' may be separate physical entities. Under such conditions, the source SO is not considered to form a part of the lithography device 100 or 100', and the radiation beam B depends on the beam delivery system BD (in FIG. 1B) including, for example, a suitable guide mirror and/or a beam expander. ) And passed from the source SO to the luminaire IL. In other situations, for example, when the source SO is a mercury lamp, the source SO may be an integral part of the lithography device 100, 100'. The source SO and the illuminator IL together with the beam delivery system BD (when needed) can be referred to as a radiation system.

The illuminator IL may include an adjuster AD (in FIG. 1B) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer radial extent and/or the inner radial extent (usually referred to as σouter and σinner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. in addition, The illuminator IL may include various other components (in FIG. 1B), such as an accumulator IN and a condenser CO. The illuminator IL can be used to adjust the radiation beam B to have a desired uniformity and intensity distribution in its cross section.

1A, the radiation beam B is incident on a patterned device (for example, a mask) MA held on a support structure (for example, a mask table) MT, and is patterned by the patterned device MA. In the lithography apparatus 100, the radiation beam B is reflected from the patterned device (for example, a photomask) MA. After being reflected from the patterned device (eg, photomask) MA, the radiation beam B passes through the projection system PS, and the projection system PS focuses the radiation beam B onto the target portion C of the substrate W. By virtue of the second positioner PW and the position sensor IF2 (for example, an interferometric device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved (for example, to position different target parts C in the path of the radiation beam B) middle). Similarly, the first positioner PM and the other position sensor IF1 can be used to accurately position the patterned device (eg, mask) MA relative to the path of the radiation beam B. The mask alignment marks M1, M2 and the substrate alignment marks P1, P2 can be used to align the patterned device (for example, the mask) MA and the substrate W.

1B, the radiation beam B is incident on a patterned device (for example, a mask MA) held on a support structure (for example, a mask table MT), and is patterned by the patterned device. When the mask MA has been traversed, the radiation beam B passes through the projection system PS, and the projection system PS focuses the beam onto the target portion C of the substrate W. The projection system has a pupil PPU that is conjugate to the pupil IPU of the illumination system. The part of the radiation diverges from the intensity distribution at the pupil IPU of the illumination system and crosses the mask pattern without being affected by the diffraction at the mask pattern, and produces an image of the intensity distribution at the pupil IPU of the illumination system.

The projection system PS projects the image MP' of the mask pattern MP onto the photoresist layer coated on the substrate W, wherein the image MP' is formed by a diffracted light beam, which is derived from the marking pattern MP is produced by radiation from the intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. The diffraction of radiation at the array that is different from the zero-order diffraction produces a diffracted beam of steering that has a direction change in the direction perpendicular to the line. The non-diffracted light beam (that is, the so-called zero-order diffracted light beam) traverses the pattern without any change in the propagation direction. The zero-order diffracted light beam traverses the upper lens or upper lens group of the projection system PS upstream of the conjugate pupil PPU of the projection system PS to reach the conjugate pupil PPU. The part of the intensity distribution associated with the zero-order diffracted beam in the plane of the conjugate pupil PPU is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. The aperture device PD is arranged, for example, at or substantially at a plane including the conjugate pupil PPU of the projection system PS.

The projection system PS is configured to capture not only the zero-order diffracted light beam, but also the first-order diffracted light beam or the first-order and high-order diffracted light beams by means of the upper lens or upper lens group L1 and the lower lens or lower lens group L2 (Figure Not shown in). In some embodiments, dipole illumination for imaging a line pattern extending in a direction perpendicular to the line can be used to take advantage of the resolution enhancement effect of dipole illumination. For example, the first-order diffracted beam interferes with the corresponding zero-order diffracted beam at the level of the wafer W, and the highest possible resolution and process window (ie, the available focus depth combined with the allowable exposure dose deviation) Generate the image MP' of the line pattern MP. In some embodiments, the astigmatism aberration can be reduced by providing a radiator (not shown in the figure) in the relative limit of the pupil IPU of the illumination system. For example, the illumination at the pupil IPU of the illumination system can only use two opposing illumination quadrants, sometimes referred to as BMW illumination, so that the remaining two quadrants are not used for illumination but are configured to capture first-order diffraction beam. In addition, in some embodiments, the astigmatism aberration can be reduced by blocking the zero-order light beam in the conjugate pupil PPU of the projection system that is associated with the radiator in the phase object limit. This situation is described in more detail in US 7,511,799 B2 issued on March 31, 2009, which is incorporated herein by reference in its entirety.

By virtue of the second positioner PW and the position sensor IF (for example, an interference device, a linear encoder, or a capacitive sensor), the substrate table WT can be accurately moved (for example, so that different target parts C are positioned between the radiation beams B). Path). Similarly, the first positioner PM and another position sensor (not shown in FIG. 1B) can be used to accurately position the mask MA relative to the path of the radiation beam B (for example, in the mechanical capture from the mask library) After fetching or during scanning).

Generally speaking, the movement of the mask table MT can be realized by the long-stroke module (coarse positioning) and the short-stroke module (fine positioning) that form the components of the first positioner PM. Similarly, the long-stroke module and the short-stroke module forming the parts of the second positioner PW can be used to realize the movement of the substrate table WT. In the case of a stepper (as opposed to a scanner), the mask stage MT can be connected to a short-stroke actuator only, or can be fixed. The mask alignment marks M1, M2 and the substrate alignment marks P1, P2 can be used to align the mask MA and the substrate W. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, the marks may be located in the spaces between the target portions (these marks are referred to as scribe lane alignment marks). Similarly, in the case where more than one die is provided on the photomask MA, the photomask alignment mark may be located between the die.

The mask stage MT and the patterned device MA may be in the vacuum chamber V, wherein the vacuum robot IVR can be used to move the patterned device such as the mask into and out of the vacuum chamber. Alternatively, when the mask stage MT and the patterning device MA are located outside the vacuum chamber, similar to the vacuum inner robot IVR, the vacuum outer robot can be used for various conveying operations. Both the robot inside the vacuum and the robot outside the vacuum need to be calibrated for smooth transfer of any payload (such as a mask) to the fixed motion installation table of the transfer station.

The lithography devices 100 and 100' can be used in at least one of the following modes:

1. In the step mode, when projecting the entire pattern given to the radiation beam B onto the target portion C at one time, the support structure (for example, the mask stage) MT and the substrate stage WT Stay essentially still (ie, a single static exposure). Then, the substrate table WT is shifted in the X and/or Y direction, so that different target portions C can be exposed.

2. In the scanning mode, when the pattern given to the radiation beam B is projected onto the target portion C, the support structure (for example, the mask stage) MT and the substrate stage WT are simultaneously scanned (that is, a single dynamic exposure ). The speed and direction of the substrate table WT relative to the support structure (for example, the mask table) MT can be determined by the magnification (reduction ratio) and the image reversal characteristics of the projection system PS.

3. In another mode, when the pattern imparted to the radiation beam B is projected onto the target portion C, the support structure (for example, the mask stage) MT is kept substantially stationary, thereby holding the programmable patterned device , And move or scan the substrate table WT. A pulsed radiation source SO can be used, and the programmable patterned device can be updated as needed after each movement of the substrate table WT or between successive radiation pulses during a scan. This mode of operation can be easily applied to maskless lithography using programmable patterned devices (such as programmable mirror arrays).

Combinations and/or variations of the described usage modes or completely different usage modes can also be used.

In another embodiment, the lithography apparatus 100 includes an extreme ultraviolet (EUV) source configured to generate a beam of EUV radiation for EUV lithography. Generally speaking, the EUV source is configured in the radiation system, and the corresponding illumination system is configured to adjust the EUV radiation beam of the EUV source.

Figure 2 shows the lithography device 100 in more detail, which includes a source collector device SO, an illumination system IL, and a projection system PS. The source collector device SO is constructed and configured such that a vacuum environment can be maintained in the enclosure structure 220 of the source collector device SO. The EUV radiation emitting plasma 210 may be formed by a plasma source generated by the discharge. Can be used by gas or steam (for example, Xe gas, Li steam Steam or Sn steam) to generate EUV radiation, in which extremely hot plasma 210 is generated to emit radiation within the EUV range of the electromagnetic spectrum. For example, the extremely hot plasma 210 is generated by causing at least part of the discharge of ionized plasma. In order to efficiently generate radiation, Xe, Li, Sn steam or any other suitable gas or steam with a partial pressure of 10 Pascals, for example, may be required. In one embodiment, an excited tin (Sn) plasma is provided to generate EUV radiation.

The radiation emitted by the thermoplasma 210 passes through an optional gas barrier or pollutant trap 230 (in some cases, also called a pollutant barrier or foil trap) positioned in or behind the opening in the source chamber 211 ) And transfer from the source chamber 211 to the collector chamber 212. The contaminant trap 230 may include a channel structure. The pollution trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. The pollutant trap or pollutant barrier 230 further indicated herein includes at least a channel structure.

The collector chamber 212 may include a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. The radiation traversing the collector CO can be reflected from the grating spectral filter 240 to be focused in the virtual source point IF. The virtual source point IF is often referred to as an intermediate focus, and the source collector device is configured such that the intermediate focus IF is located at or near the opening 219 in the enclosure 220. The virtual source point IF is an image of the radiation emission plasma 210. The grating spectral filter 240 is particularly used to suppress infrared (IR) radiation.

Subsequently, the radiation traverses the illumination system IL. The illumination system IL may include a faceted field mirror device 222 and a faceted pupil mirror device 224. The faceted field mirror device 222 and the faceted pupil mirror device 224 are configured to The desired angular distribution of the radiation beam 221 at the patterned device MA and the desired uniformity of the radiation intensity at the patterned device MA are provided. After the reflection of the radiation beam 221 at the patterned device MA held by the support structure MT, a patterned beam 226 is then formed, and the patterned beam 226 is transmitted through the reflective elements 228, 230 by the projection system PS. The image is imaged onto the substrate W held by the wafer stage or the substrate table WT.

More components than the ones shown can usually be present in the illumination optics unit IL and the projection system PS. Depending on the type of lithography device, a grating spectral filter 240 may be present. In addition, there may be more mirrors than those shown in FIG. 2, for example, there may be 1 to 6 additional reflective elements in the projection system PS than the reflective elements shown in FIG. 2.

The collector optics CO as illustrated in FIG. 2 is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, just as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254, and 255 are arranged to be axially symmetrical around the optical axis O, and this type of collector optics CO is preferably used in combination with a discharge generating plasma source (often referred to as a DPP source) .

Exemplary lithography manufacturing unit

FIG. 3 shows a lithography manufacturing cell 300, which is sometimes referred to as a lithography manufacturing cell (lithocell) or cluster. The lithography device 100 or 100' may form part of the lithography manufacturing unit 300. The lithography manufacturing unit 300 may also include one or more devices for performing a pre-exposure process and a post-exposure process on the substrate. Generally, these devices include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a baking plate BK. The substrate handler or robot RO picks up the substrate from the input/output ports I/O1 and I/O2, moves the substrate between different process devices, and delivers the substrate to the loading tray LB of the lithography device 100 or 100'. These devices, which are often collectively referred to as coating and development systems, are under the control of the coating and development system control unit TCU. The coating and development system control unit TCU itself is controlled by the supervisory control system SCS. The supervisory control system SCS is also controlled by the photolithography system. The control unit LACU controls the lithography device. Therefore, different devices can be operated to maximize throughput and processing efficiency.

Exemplary Scatterometer

In order to ensure the correct and consistent exposure of the substrate exposed by the lithography device (such as the lithography device 100 and/or 100'), it is necessary to inspect the exposed substrate to measure such as the stacking error between subsequent layers, line thickness, and criticality. Attributes such as size (CD). If an error is detected, the subsequent substrate exposure can be adjusted, especially if the inspection can be completed quickly and quickly enough before other substrates in the same batch are exposed. In addition, the exposed substrate can be stripped and reworked-to improve yield-or discarded, thereby avoiding exposure to known defective substrates. In a situation where only some target portions of the substrate are defective, further exposure can be performed only on those target portions that are acceptable.

The detection device can be used to determine the properties of the substrate, and in particular to determine how the properties of different substrates or different layers of the same substrate vary from layer to layer. The detection device may be integrated into the lithography device (such as the lithography device 100 and/or 100') or the lithography manufacturing unit 300, or may be a stand-alone device. In order to achieve rapid measurement, it is necessary to make the inspection device measure the properties in the exposed resist layer immediately after the exposure. However, the latent image in the resist has extremely low contrast-there is only a very small refractive index difference between the part of the resist that has been exposed to radiation and the part of the resist that has not been exposed to radiation-and not all The detection devices have sufficient sensitivity to make useful measurements of latent images. Therefore, the measurement can be performed after the post-exposure bake step (PEB). The post-exposure bake step (PEB) is usually the first step performed on the exposed substrate and increases the exposed and unexposed parts of the resist The contrast between. At this stage, the image in the resist can be called semi-latent. It is also possible to measure the image of the developed resist-at this time, the exposed or unexposed part of the resist has been removed-or develop it after a pattern transfer step such as etching Measurement of resist image. The latter possibility limits the possibility of reworking defective substrates, but can still provide useful information.

Figure 4 depicts a scatterometer SM1 that can be used in the present invention. Scatterometer SM1 can be adjusted It is incorporated into a lithography device (such as the lithography device 100 and/or 100') or the lithography manufacturing unit 300, or may be a stand-alone device. The scatterometer SM1 includes a broadband (white light) radiation projector 2 that projects radiation onto the substrate W. The reflected radiation is transmitted to the spectrometer detector 4, which measures the spectrum 10 (intensity that varies depending on the wavelength) of the radiation reflected by the mirror. From this data, the structure or profile of the detected spectrum can be reconstructed by the processing unit PU, for example, by rigorous coupled wave analysis and nonlinear regression, or by comparing the simulated spectrum library shown at the bottom of Figure 4 Compare. Generally speaking, for reconstruction, the general form of the structure is known, and some parameters are assumed based on the knowledge of the manufacturing process used to manufacture the structure, so that only a few parameters of the structure are left to be judged by self-scattering measurement data. This scatterometer can be configured as a normal incident scatterometer or an oblique incident scatterometer.

Figure 5 shows another scatterometer SM2 that can be used with the present invention. The scatterometer SM2 may be integrated into a lithography apparatus (such as the lithography apparatus 100 and/or 100') or the lithography manufacturing unit 300, or may be a stand-alone device. The scatterometer SM2 may include an objective optical system 1, which has: a radiation source 2, a lens system 12, a filter 13 (for example, an interference filter), a reflecting device 14 (for example, a reference mirror), and a lens system 15 (For example, a microscope objective lens system, which is also referred to herein as an objective lens system), a partially reflective surface 16 (for example, a beam splitter), and a polarizer 17. The scatterometer SM2 may further include a detector 18 and a processing unit PU.

In an exemplary operation, the lens system 12 is used to collimate the radiation emitted by the radiation source 2 and transmit the radiation through the interference filter 13 and the polarizer 17, the radiation is reflected by the partially reflective surface 16, and the radiation It is focused on the substrate W through the microscope objective lens system 15. The reflected radiation is then transmitted through the partially reflective surface 16 into the detector 18 so that the scattered spectrum can be detected. The detector may be located in the back-projection pupil plane 11, which is at the focal length F of the objective lens system 15. However, the pupil plane may instead use auxiliary optics (not shown in the figure) ) And then image onto the detector 18. The pupil plane is defined as the radial position of radiation The angle of incidence and angular position define the plane of the azimuth of radiation. In one example, the detector is a two-dimensional detector, so that the two-dimensional angular scattering spectrum of the substrate target 30 can be measured. The detector 18 can be, for example, a CCD or CMOS sensor array, and can be used as, for example, an integration time of 40 milliseconds per frame.

The reference beam can be used, for example, to measure the intensity of incident radiation. To perform this measurement, when the radiation beam is incident on the beam splitter 16, part of the radiation beam faces the reference mirror 14 as a reference beam and transmits through the beam splitter. The reference beam is then projected onto different parts of the same detector 18 or alternatively onto different detectors (not shown in the figure).

The interference filter 13 may include a set of interference filters, which can be used to select a wavelength of interest in the range of, for example, 405 nm to 790 nm, or a lower range of, for example, 200 nm to 300 nm. The interference filter can be tunable instead of including a set of different filters. Alternatively, instead of the interference filter, for example, a grating may be used.

The detector 18 can measure the intensity of scattered light at a single wavelength (or narrow wavelength range), the intensity of scattered light at multiple wavelengths separately, or the intensity of scattered light integrated over a wavelength range. In addition, the detector 18 can separately measure the intensity of the transverse magnetic polarization and the transverse electrical polarization, and/or the phase difference between the transverse magnetic polarization and the transverse electrical polarization.

The broadband light source using the radiation source 2 (ie, a broadband light source with a wide range of light frequencies or wavelengths-and therefore a wide range of colors) can give a large elongation, thereby allowing multiple wavelengths to be mixed. Preferably, the plurality of wavelengths in the wide frequency band may each have a bandwidth of Δλ and a distance of at least 2Δλ (that is, twice the bandwidth). Several radiation "sources" can be different parts of an extended radiation source that has been split using fiber bundles. In this way, angle-resolved scattering spectra can be measured at multiple wavelengths in parallel. It can measure 3-D spectrum (wavelength and two different angles), which contains more information than 2-D spectrum. This allows more information to be measured, this situation increases The stability of the weights and measures process is improved. This situation is described in more detail in EP 1628164 A2, which is incorporated herein by reference in its entirety.

The target 30 on the substrate W may be a 1-D grating, which is printed such that after development, the strips are formed by solid resist lines. The target 30 may be a 2-D grating, which is printed such that after development, the grating is formed by solid resist guide posts or through holes in the resist. Strips, guide posts, or vias may alternatively be etched into the substrate. This pattern is sensitive to chromatic aberration and illumination symmetry in the lithographic projection device (especially the projection system PS). The existence of such aberrations will make itself appear as changes in the printed grating. Therefore, the scattering measurement data of the printed grating is used to reconstruct the grating. The parameters of the 1-D grating (such as line width and shape) or the parameters of the 2-D grating (such as the width or length or shape of the guide post or through hole) can be input to the self-printing step and/or other scattering by the processing unit PU Reconstruct the process by measuring the knowledge of the process.

As described above, the target can be on the surface of the substrate. This target will often take the shape of a series of lines in a grating or a substantially rectangular structure in a 2-D array. The purpose of the strict optical diffraction theory in metrology is actually to calculate the diffraction spectrum reflected from the target. In other words, the target shape information is obtained for the uniformity of critical dimeiision (CD) and overlap measurement. Overlap metrology is a measurement system that measures the overlap of two targets in order to determine whether the two layers on the substrate are aligned. CD uniformity is only a measurement of the uniformity of the grating on the spectrum used to determine how the exposure system of the lithography device operates. In particular, the critical dimension (or CD) is the width of the object "written" on the substrate, and is the limit that the lithography device can physically write on the substrate.

Use the "dark field" scattering measurement based on the diffraction-based stack to block zero-order diffraction (corresponding to specular reflection), and only process one or more high-order diffractions to generate a gray-scale image of the target. Diffraction-based stacking using this dark-field technology realizes stacking measurement of smaller targets, And it is called micro-diffraction based overlay (μDBO). μDBO may require extremely high contrast ratios.

Exemplary optical system

稜鏡 is a wedge-shaped transparent optical element that separates electromagnetic (EM) radiation due to a difference in refractive index based on refraction. Generally, the scallop has a flat polished surface. The cross-section of the 稜鏡 is polygonal, and the sides of the 稜鏡 are anti-parallel. The scallop may include a plurality of surfaces, and the angle between the surfaces of the scallop can vary, but there must be a certain angle between at least two surfaces. The beam splitting beam is a type of reflective beam configured to split the beam into two or more beams. The polarization beam is a type of beam configured to split the light beam into varying polarization components based on nonlinear optics.

Non-linear optics (NLO) refers to EM radiation in a nonlinear medium, which means that the polarization of the medium (that is, the electric dipole moment) and the electric field of the EM radiation interact nonlinearly. The normal linear relationship between the electric field and the dielectric electric field collapses in a nonlinear medium. Non-linear interactions can make themselves appear as changes in polarization, frequency, phase, and/or beam path.

The nonlinear prismatic optical member may have a nonlinear refractive index change. For example, birefringent materials have a refractive index that depends on the polarization and propagation direction of EM radiation. Birefringent nonlinear media cause birefringence, where unpolarized EM radiation is split into two beam paths with parallel and perpendicular polarization. The birefringent nonlinear medium is composed of two polarized wave components corresponding to different refractive indexes. Normal rays (o-rays) have polarization in the direction perpendicular to the optical axis, while abnormal rays (e-rays) that do not follow Snell's law have polarization in the direction of the optical axis of the medium.

The Wollaston beam is a nonlinear prismatic optical element that separates the EM radiation according to the polarization component of the EM radiation. Wollaston’s beam separates unpolarized EM radiation into orthogonal ones Polarized beam. Generally, Wollaston's ridges include two right-angled triangular ridges that are fastened (for example, glued, glued, etc.) together on the surface of each ridge to form a cube. The outgoing radiation beam from Wollaston's beam diverges based on the wedge angle and wavelength of the EM radiation, and is split into two orthogonally polarized beams. The range of the divergence angle depending on the wedge angle may be about 1° to 45°.

FIG. 6 is a schematic illustration of an exemplary optical system 600 used in an exemplary detection device IA according to some embodiments of the present invention. Although the optical system 600 is shown as being used with the detection device IA, the embodiment of the present invention is not limited to this example and the optical system embodiment of the present invention can be used with other optical systems, such as but not limited to the lithography device 100 and/ Or 100', lithography manufacturing unit 300, scatterometer SM1, scatterometer SM2, and/or other optical systems.

For example, FIG. 6 illustrates the objective optical system 1 of the scatterometer SM2 of FIG. 5, the detector 18 of the scatterometer SM2 of FIG. 5, the processing unit PU of the scatterometer SM2 of FIG. 5, and the optical system 600. According to some examples, the optical system 600 is configured to receive a zero-diffraction-order beam 617a and a diffraction-order beam 617b reflected from a diffraction target (such as the substrate target 30 of the substrate W in FIG. 5).

According to some embodiments, the optical system 600 may be configured to generate the first polarization zero-order sub-beam 623a and the second polarization zero-order sub-beam 629a from the zero diffraction order beam 617a. In addition, the optical system 600 can be configured to generate a first-polarized first-order sub-beam 623b and a second-polarized first-order sub-beam 629b from a diffraction order beam 617b. In some embodiments, the detector 18 can receive the sub-beams 623a, 623b, 629a, and 629b, and measure the intensity and/or polarization of the sub-beams 623a, 623b, 629a, and 629b. The detector 18 and the processing unit PU may be configured to measure one or more parameters of the substrate W, the substrate target 30, and/or the optical system (such as a lithography device) used to generate the substrate W. In some embodiments, the detector 18 and the processing unit PU can be configured to measure on the substrate W The parameters of the substrate target 30, such as the stacking error between successive layers formed in or on the patterned substrate W and/or the critical line width of the developed photosensitive resist.

In some embodiments, the first polarization zero-order sub-beam 623a can be the linear horizontal (H) polarization component of the zero-diffraction order beam 617a, and the second polarization zero-order sub-beam 629a can be the linear of the zero-diffraction order beam 617a. The vertical (V) polarization component, which is orthogonal to the linear horizontal (H) polarization component 623a. In some embodiments, the first-polarization first-order sub-beam 623b can be a linear horizontal (H) polarization component of the diffraction order beam 617b, and the second-polarization first-order sub-beam 629b can be a linear diffraction order beam 617b. The vertical (V) polarization component, which is orthogonal to the linear horizontal (H) polarization component 623b.

According to some examples, the zero-diffraction order beam 617a and the one-diffraction order beam 617b can be unpolarized radiation beams. The optical system 600 can be configured to split these unpolarized input beams (617a and 617b) into their levels (H) And the vertical (V) polarization component and output the resulting sub-beams (623a and 629a) from the input beam 617a and the sub-beams (623b and 629b) from the input beam 617b, each of which, for example, travels parallel to and adjacent to each other. The optical system of the embodiment of the present invention can be configured to image the H and V polarized light beams onto a single detector (e.g., sensor) 18 at a common focal plane. For example, the detector 18 may be a single dark field detector that receives H and V polarized light beams. Polarized radiation with its electric field along the plane of incidence is considered to be p- polarized (that is, transverse magnetic (TM)), and polarized radiation with its electric field perpendicular to the plane of incidence is considered to be s- polarized (that is, transverse electric (TE)). In one example, the sub-beams 623a and 623b may have horizontal (H) polarization information and p- polarization orientation. And for example, the sub-beams 629a and 629b may have vertical (V) polarization information and p- polarization orientation.

According to some exemplary embodiments, the optical system 600 may also include one or more quarter wave plates (QWP) (not shown in FIG. 6) and/or one or more mirror surfaces (not shown in FIG. 6). Show). The QWP may include, for example, a QWP polymer stack or a QWP coating applied to the mirror surface. Alternatively, according to some embodiments, the optical system 600 may be designed such that the optical system 600 does not include any QWP. In some examples, the optical system 600 may be designed to use total internal reflection (TIR) in the optical system 600 with or without a mirror surface.

According to some exemplary embodiments, the optical system 600 may be designed such that the sub-beams 623a, 629a, 623b, and 629b travel through the optical system 600 in the same or substantially the same optical path. In the context of the present invention, the term "substantially the same optical path" means that the path difference is such that the sub-beams are focused on the detector within the focal depth of the image formed by the sub-beams after propagating through the optical system 600 18 locations. The depth of focus can vary depending on, for example, radiation wavelength, sub-beam numerical aperture, and/or aberrations. In other words, according to some exemplary embodiments, the optical system 600 may be designed such that the optical paths for the sub-beams 623a, 629a, 623b, and 629b to pass through the optical system 600 have the same or substantially the same length. Additionally or alternatively, the optical system 600 may be designed such that the output surface, input surface, and/or other surfaces of the optical system 600 are inclined with respect to the optical paths of the sub-beams 623a, 629a, 623b, and 629b. According to some examples, these tilts can prevent or minimize "ghosting" reflections from these surfaces from overlapping with the primary beam on the detector (such as detector 18).

)、百分比(例如(

)＊100)，或作為 以分貝(dB)為單位之函數(例如10＊log

))。此處，T₂可為非想要分量(例 如，不當的偏振)之透射率(例如，功率)且T₁可為想要分量(例如，所要偏 振)之透射率(例如，功率)。偏振消光比為取決於輻射光束之波長之屬性。作為一項實例，可將非偏振輻射光束分裂成具有p偏振定向之子光束及具有s偏振定向之另一子光束。經p偏振之子光束可透射通過光學系統600且經s偏振之子光束可自光學系統600反射。可將經s偏振之子光束之偏振消光比定義為由光學系統600反射之輻射光束之非想要部分對由光學系統600反射之想要的經s偏振之子光束的比率。 In additional or alternative embodiments, one of the sub-beams 623a or 629a (and one of the sub-beams 623b or 629b) may be transmitted through the surface of the optical system 600 twice or reflected from the surface of the optical system 600 twice to achieve A predetermined polarization extinction ratio (PER). The polarization extinction ratio can be defined as the transmission ratio of the unwanted component to the desired component. The polarization extinction ratio can be expressed as a linear ratio (e.g.

), percentage (e.g. (

)*100), or as a function in decibels (dB) (e.g. 10* log

)). Here, T ₂ can be the transmittance (e.g., power) of the undesired component (e.g., improper polarization) and T ₁ can be the transmittance (e.g., power) of the desired component (e.g., the desired polarization). The polarization extinction ratio is a property that depends on the wavelength of the radiation beam. As an example, a non-polarized radiation beam can be split into a sub-beam with p- polarization orientation and another sub-beam with s-polarization orientation. The p- polarized sub-beam can be transmitted through the optical system 600 and the s- polarized sub-beam can be reflected from the optical system 600. The polarization extinction ratio of the s- polarized sub-beam can be defined as the ratio of the unwanted part of the radiation beam reflected by the optical system 600 to the desired s- polarized sub-beam reflected by the optical system 600.

Figure 7 illustrates an exemplary optical system 750 used in an exemplary detection device 700 according to some embodiments. According to some embodiments, the detection device IA of FIG. 6 may include the optical system 750 of FIG. 7. For example, the optical system 600 of FIG. 6 may be the optical system 750 of FIG. 7. Thus, the optical system 750 can receive the zero diffraction order beam 617a and the one diffraction order beam 617b, as discussed above with respect to FIG. 6. However, the optical system 750 can be located in any part of a lithography device, a metrology device, and the like.

As shown in FIG. 7, the detection device 700 may include an optical system 750, a lens system 730, and a detector 740. The detection device 700 can receive, for example, a first (-0) zero-order sub-beam 702, a second (+0) zero-order sub-beam 704, a first (-1) ) The first-order sub-beam 706 and the second (+1) first-order sub-beam 708. In some embodiments, the sub-beams 702, 704, 706, and 708 are generated and isolated by dipole or quadrupole illumination radiators (not shown in the figure). For example, the sub-beams 702, 704, 706, and 708 can be generated and isolated by using only two relative illumination quadrants (sometimes referred to as BMW illumination), so that the remaining two quadrants are not used for illumination but are grouped together. To capture the first (-1) first-order sub-beam 706 and the second (+1) first-order sub-beam 708. In some embodiments, the radiator (not shown in the figure) in the relative confinement of the lighting system (for example, including the radiation source 2 in FIG. 5) can generate and isolate the sub-beams 702, 704, 706, and 708. In addition, in some embodiments, it is possible to block the zero-order beam associated with the radiator in the relative confinement. Reduce astigmatism aberration. The full text of each is incorporated herein by reference. This lighting technology is described in more detail in US 7,511,799 B2 issued on March 31, 2009 and US 8,830,447 B2 issued on September 9, 2014.

The optical system 750 may include a first nonlinear prismatic optical element 710 and a second nonlinear prismatic optical element 720. In other examples (not shown in the figure), the optical system 750 may include more than two nonlinear prismatic optical elements.

For example, the first non-linear prismatic optical element 710 and the second non-linear prismatic optical element 720 may each be a Wollaston prism, as shown in FIG. 7. For example, the first nonlinear prismatic optical element 710 may include a first right-angled triangle orthogonal ridge 712 and a second right-angled triangle orthogonal ridge 714, and the second nonlinear prismatic optical element 720 may include a first right angle. The triangle orthogonal 722 and the second right triangle orthogonal 724. The first right-angled triangle orthogonal cube 712 and the second right-angled triangle orthogonal cube 714 can form, for example, a first integral cube, such as the first Wollaston cube. In addition, the first right-angled triangle orthogonal 722 and the second right triangle orthogonal 724 can form a second integral cube, such as the second Wollaston cube.

The optical system 750 is configured to separate/generate two polarization components of at least two different diffraction orders. For example, the first nonlinear prismatic optical element 710 can receive the first (-0) zero-order input sub-beam 702 and the second (+0) zero-order input sub-beam 704, and generate/separate (a) the first Polarized first (-0) zero-order output sub-beam 716a and second polarization first (-0) zero-order output sub-beam 716b and (b) first polarization second (+0) zero-order output sub-beam 718a and the second (+0) zero-order output sub-beam 718b of the second polarization. In some embodiments, the output sub-beams 716a and 718a may be linear horizontal (H) polarization components of the input sub-beams 702 and 704, respectively. And the output sub-beams 716b and 718b can be the linear vertical (V) polarization components of the input sub-beams 702 and 704, respectively, which are orthogonal to the linear horizontal (H) polarization components 716a and 718a. For example, the second nonlinear prismatic optical element 720 receives the first (-1) first-order input sub-beam 706 and the second (+1) first-order input sub-beam 708, and generates/separates (a) the first (-1) first-order output sub-beam of the first polarization 726a and the first (-1) first-order output sub-beam of the second polarization 726b and the second (+1) first-order output sub-beam of the first polarization 728a and the second (+1) first-order output sub-beam of the second polarization光光728b. In some embodiments, the output sub-beams 726a and 728a may be linear horizontal (H) polarization components of the input sub-beams 706 and 708, respectively. And the output sub-beams 726b and 728b can be the linear vertical (V) polarization components of the input sub-beams 706 and 708, respectively, which are orthogonal to the linear horizontal (H) polarization components 726a, 728a.

In some embodiments, the first nonlinear prismatic optical element 710 and the second nonlinear prismatic optical element 720 are configured differently, and the first nonlinear prismatic optical element 710 and the second nonlinear prismatic optical element 720 are configured differently. Different types of nonlinear prismatic optical parts. For example, the triangular ridges 712 and 714 of the first nonlinear prism-shaped optical element 710 are fastened (for example, glued, glued, joined, etc.) at the wedge connection 711, which is connected to the wedge connection 711 and parallel to the first nonlinear prism A wedge angle 713 is formed between the horizontal cross-sections of the base of the shaped optical element 710. The divergence angles 715a and 715b of the output sub-beams 716a, 716b and 718a, 718b depend on the wedge angle 713, respectively. For example, the triangular ridges 722, 724 of the second nonlinear prism-shaped optical element 720 are fastened (for example, glued, glued, bonded, etc.) at the wedge connection 721, which is connected to the wedge connection 721 and parallel to the second nonlinear prism. A wedge angle 723 is formed between the horizontal cross-sections of the base of the shaped optical element 720. The divergence angles 725a and 725b of the output sub-beams 726a, 726b and 728a, 728b depend on the wedge angle 723, respectively. In some embodiments, the wedge angle 713 may form divergence angles 715a, 715b, which are larger than the wedge angle 723 formed by the second nonlinear prismatic optical element 720 and the corresponding divergence angles 725a, 725b. In some embodiments, the wedge angle 713 (and the divergence angles 715a, 715b) of the first nonlinear prismatic optical element 710 may be about 45°, for example, so that the output sub-beams 716a and 716b (and the output sub-beams 718a and 718b) After the first nonlinear prismatic optical element 710 is emitted, the separation/divergence is about 45°. In some implementation In an example, the wedge angle 723 (and the divergence angles 725a, 725b) of the second nonlinear prismatic optical element 720 may be approximately 15°, so that the output sub-beams 726a and 726b (and the output sub-beams 728a and 728b) are emitted at the first The rear separation/divergence of the bi-nonlinear prismatic optical element 720 is 15°. In some embodiments, the first nonlinear prismatic optical element 710 may be thicker than the second nonlinear prismatic optical element 720 so that the input sub-beams 702 and 704 travel a longer path through the first nonlinear prismatic optical element 710. For example, the longer path can reduce the intensity of the input sub-beams 702 and 704 due to the absorption and/or scattering of the input sub-beams 702 and 704 in the first nonlinear prismatic optical element 710. In some embodiments, the second nonlinear prismatic optical element 720 may be thicker than the first nonlinear prismatic optical element 710 so that the input sub-beams 706 and 708 travel a longer path through the second nonlinear prismatic optical element 720.

The detection device 700 also includes a lens system 730. The lens system 730 is disposed between the optical system 750 and the detector 740. For example, the lens system 730 may be placed at the focal length F so as to focus the outgoing sub-beams 716a, 716b, 718a, 718b, 726a, 726b, 728a, and 728b onto the detector 740. In some embodiments, the lens system 730 can arrange the sub-beams 716a, 716b, 718a, 718b, 726a, 726b, 728a, and 728b into a pre-configured pattern on the detector 740. In some embodiments, the optical system 750 is located at the pupil plane of the detection device 700. The pupil plane is the plane where the radial position of the radiation defines the angle of incidence and the angular position defines the azimuth angle of the radiation. Although the lens system 730 is illustrated as a single optical element, the lens system 730 may be composed of two or more optical elements. In some embodiments, the lens system 730 may be omitted from the detection device 700.

The detection device 700 also includes a detector 740. The detector 740 can detect and/or sense the energy (such as photons, EM radiation) irradiated on the surface of the detector 740. For example, the detector 740 may include a photosensitive region in which light generation (such as electron-hole pairs) occurs And/or the transfer of photons to electrons, and the detector 740 can measure the movement of the charge generated by the irradiation energy. In some embodiments, the detector 740 may be a single detector used to image the sub-beams 716a, 716b, 718a, 718b, 726a, 726b, 728a, and 728b. For example, the detector 740 can be a single dark field or phase difference detector (such as CCD, CMOS, etc.), which excludes or blocks the unscattered illumination beam (such as the radiation source 2 in FIG. 5) from entering the optical system 750. In some embodiments, the detector 740 may be a quadrant detector with four individual photosensitive regions for energy detection.

The detection device 700 or the optical system 750 may include one or more neutral density filters ND. The neutral density filter ND is an optical filter that equally reduces or modifies (for example, by partial reflection) the intensity of the illuminating radiation. In some embodiments, as shown in FIG. 7, the neutral density filter ND may be placed on the incident first (-0) and second (+0) zero-order sub-beams and the first nonlinear prismatic optical element Between 710. The neutral density filter ND is configured to reduce the intensity of the zero-order diffracted beams 702, 704, which can be higher than the intensity of the first-order diffracted beams 706, 708, and irradiate them on the detector 740 with normalization. The intensity of all zero-order sub-beams 716a, 716b, 718a, 718b and first-order sub-beams 726a, 726b, 728a, 728b. For example, the neutral density filter ND can normalize the first (-0) zero-order sub-beam with respect to the intensity of the first (-1) first-order sub-beam 706 and the second (+1) first-order sub-beam 708 The intensity of the beam 702 and the second (+0) zero-order sub-beam 704. In some embodiments, the detection device 700 or the optical system 750 may omit the neutral density filter ND. Alternatively, in some embodiments, the neutral density filter ND may be omitted, and the first nonlinear prismatic optical element 710 may be configured to be thicker in size than the second nonlinear prismatic optical element 720. For example, the thickness of the first nonlinear prismatic optical element 710 can be designed to normalize the intensity of the first (-1) first-order sub-beam 706 and the second (+1) first-order sub-beam 708. The intensity of the (-0) zero-order sub-beam 702 and the second (+0) zero-order sub-beam 704.

Figure 8 illustrates an exemplary optical system 800 according to some embodiments. According to some examples, the optical system 800 includes a 2×2 matrix array 802 of nonlinear prismatic optics 810, 820, 830, and 840. In some embodiments, as shown in FIG. 8, a 2×2 matrix array 802 of nonlinear prismatic optical elements 810, 820, 830, and 840 are disposed on the transparent plate 804. The transparent plate 804 maintains the positional relationship between the nonlinear prismatic optical elements 810, 820, 830, and 840. In some embodiments, the plate 804 is omitted, and the 2×2 matrix array 802 is placed in an optical frame or cage (not shown in the figure), which is configured to form a nonlinear prismatic The optics 810, 820, 830, and 840 are fastened in position relative to each other.

According to some embodiments, the detection device 700 of FIG. 7 may include the optical system 800 of FIG. 8. For example, the optical system 750 of FIG. 7 may be the optical system 800 of FIG. 8. The optical system 800 can be positioned near the detector 4 of FIG. 4 and/or the detector 18 of FIG. 5 and/or FIG. 6 and/or the detector 740 of FIG. 7. The optical system 800 can be configured to receive the zero-order beam 617a and the first-order beam 617b as discussed above in relation to FIG. 6, or the zero-order sub-beams 702, 704, and the first-order beam as discussed above in relation to FIG. Sub-beams 706,708. However, the optical system 800 can be located in any part of a lithography device, a metrology device, and the like. Although FIG. 8 illustrates a 2×2 matrix array, the optical system 800 may include arrays having different sizes.

The optical system 800 may include a first nonlinear prismatic optical element 810, a second nonlinear prismatic optical element 820, a third nonlinear prismatic optical element 830, and/or a fourth nonlinear prismatic optical element 840. For example, the non-linear prismatic optical elements 810, 820, 830, and 840 may each be Wollaston horns. Alternatively, in some embodiments, the nonlinear prism-shaped optical elements 810, 820, 830, and 840 may each be a birefringent optical element, a Nomarski prism, a Senna montain, a Los Angeles prism, a Glan -Thompson jewels, and/or Gran Foucault jewels. Alternatively, in some embodiments, the nonlinear prismatic optical element 810, 820, 830, and/or 840 may be birefringent light Scientific components, Wollaston magma, Nomarski magma, Sennamont magma, Lohung magma, Gran-Thompson magma, and/or Glan-Fucault magma. In some embodiments, the transparent plate 804 may be an orthotope of transparent glass ridges. Again, in some embodiments, the transparent plate 804 may be omitted.

In some embodiments, the first nonlinear prism-shaped optical element 810 includes a first right-angled triangle orthogonal ridge 812 and a second right-angled triangle orthogonal ridge 814. For example, as shown in FIG. 8, the first right-angled triangle orthogonal ridge 812 and the second right-angled triangle orthogonal ridge 814 of the first nonlinear prism-shaped optical element 810 are fastened (e.g., glued, glued, joined, etc.) ) At the wedge connection (not shown in the figure), which forms a wedge angle (figure Not shown in). The divergence angle (not shown in the figure) of the output sub-beam (not shown in the figure) depends on the wedge angle (not shown in the figure). In some embodiments, the range of the wedge angle (not shown in the figure) and the corresponding divergence angle (not shown in the figure) of the first nonlinear prismatic optical element 810 may be about 1° to 45°. For example, the first right-angled triangle orthogonal 812 and the second right-angled triangle orthogonal 814 can form a cube with a wedge angle of 45° (not shown in the figure).

In some embodiments, the first nonlinear prismatic optical element 810 may be a first Wollaston prism 810 belonging to the first type, which is configured to have greater than third nonlinear prismatic optical elements 830 and The wedge angle 835 and/or the wedge angle (not shown in the figure) and the divergence angle (not shown in the figure) of the wedge angle 835 and/or the wedge angle 845 of the fourth nonlinear prismatic optical element 840 are, for example, a wedge angle of 45°. The first non-linear prismatic optical element 810 receives the first (-0) zero-order sub-beam 816 and separates/generates the first (-0) zero-order sub-beams of the first and second polarizations (not shown in the figure). In some embodiments, for example, the sub-beam (not shown in the figure) can be the linear horizontal (H) polarization component of the first (-0) zero-order sub-beam 816, and the sub-beam (not shown in the figure) ) Can be the linear vertical (V) deviation of the first (-0) zero-order sub-beam 816 The vibration component, which is orthogonal to the linear horizontal (H) polarization component. In some embodiments, as shown in FIG. 8, the first right-angled triangle orthogonal horn 812 has an optical axis in the vertical (V) direction indicated by the vertical arrow, so as to separate/generate the input sub-beam 816 The linear vertical (V) polarization component (not shown in the figure), and the second right-angled triangle orthogonal beam 814 has an optical axis in the horizontal (H) direction to separate/generate the linear horizontal (H) input sub-beam 816 ) Polarization component (not shown in the figure).

The second nonlinear prismatic optical element 820 is similar to the first nonlinear prismatic optical element 810. In some embodiments, the second nonlinear prism-shaped optical element 820 includes a first right-angled triangle orthogonal 822 and a second right-angled triangle orthogonal 824. For example, as shown in FIG. 8, the first right-angled triangle orthogonal 822 and the second right triangle orthogonal 824 of the second nonlinear prismatic optical element 820 are fastened (e.g., glued, glued, joined, etc.) ) At the wedge connection 823, it forms a wedge angle 825 between the wedge connection 823 and the horizontal cross section parallel to the base of the second nonlinear prismatic optical element 820. The divergence angle 827 of the output sub-beams 828a and 828b depends on the wedge angle 825. In some embodiments, the wedge angle 825 and the corresponding divergence angle 827 of the second nonlinear prismatic optical element 820 may range from about 1° to 45°. For example, the first right-angled triangle orthogonal 822 and the second right triangle orthogonal 824 can form a cube with a wedge angle 825 of 45°.

In some embodiments, the second non-linear prismatic optical element 820 may be a second Wollaston prism 820 belonging to the first type, which is configured to have greater than the third non-linear prismatic optical element 830 and The wedge angle 835 and/or the wedge angle 825 and the divergence angle 827 of the wedge angle 845 of the fourth nonlinear prismatic optical element 840 are, for example, a wedge angle 825 of 45°. The second nonlinear prismatic optical element 820 receives the second (+0) zero-order sub-beam 826 and separates/generates the second (+0) zero-order sub-beam 828a of the first polarization and the second (+0) ) Zero-order sub-beam 828b. In some embodiments, for example, the sub-beam 828a may be the linear horizontal (H) polarization component of the second (+0) zero-order sub-beam 826, and the sub-beam 828b may be the second (+0) zero-order sub-beam The linear vertical (V) polarization component of beam 826, It is orthogonal to the linear horizontal (H) polarization component 828a. In some embodiments, as shown in FIG. 8, the first nonlinear prismatic optical element 810 and the second nonlinear prismatic optical element 820 are rotated 90° relative to each other around the optical axis. In some embodiments, as shown in FIG. 8, the first right-angled triangle orthogonal scallop 822 has an optical axis in the horizontal (H) direction indicated by the horizontal arrow to separate/generate the linear horizontal of the input sub-beam 826 The (H) polarization component 828a, and the second right-angled triangle orthogonal beam 824 has an optical axis in the vertical (V) direction to separate/generate the linear vertical (V) polarization component 828b of the input sub-beam 826.

In some embodiments, the third nonlinear prismatic optical element 830 includes a first orthogonal ridge 832 and a second orthogonal ridge 834. For example, as shown in FIG. 8, the first orthogonal ridge 832 and the second orthogonal ridge 834 of the third nonlinear prismatic optical element 830 are fastened (such as glued, glued, joined, etc.) to the wedge connection At 833, it forms a wedge angle 835 between the wedge connection 833 and the horizontal cross section parallel to the base of the third nonlinear prismatic optical element 830. The divergence angle 837 of the output sub-beams 838a and 838b depends on the wedge angle 835. In some embodiments, the wedge angle 835 and the corresponding divergence angle 837 of the second nonlinear prismatic optical element 830 may range from about 1° to 45°. For example, the first right-angled triangle orthogonal 832 and the second right-angled triangle orthogonal 834 can form a cube with a wedge angle 835 of 15°.

In some embodiments, the third nonlinear prismatic optical element 830 may be a third Wollaston prism 830 belonging to the second type, which is configured to have a smaller size than the first nonlinear prismatic optical element 810 and The wedge angle (not shown in the figure) and/or the wedge angle 835 and the divergence angle 837 of the wedge angle 825 of the second nonlinear prismatic optical element 820 are, for example, a wedge angle 835 of 15°. The third nonlinear prismatic optical element 830 receives the first (-1) first-order sub-beam 836 and splits/generates the first (-1) first-order sub-beam 838a of the first polarization and the first (-1) first-order sub-beam of the second polarization ) First-order sub-beam 838b. In some embodiments, for example, the sub-beam 838a may be the linear level (H) of the first (-1) first-order sub-beam 836 The polarization component, and the sub-beam 838b may be the linear vertical (V) polarization component of the first (-1) first-order sub-beam 836, which is orthogonal to the linear horizontal (H) polarization component 838a. In some embodiments, as shown in FIG. 8, the first right-angled triangle orthogonal horn 832 has an optical axis in the vertical (V) direction indicated by the vertical arrow, so as to separate/generate the input sub-beam 836 The linear vertical (V) polarization component 838b, and the second right-angled triangle orthogonal beam 834 has an optical axis in the horizontal (H) direction to separate/generate the linear horizontal (H) polarization component 838a of the input sub-beam 836.

The fourth nonlinear prismatic optical element 840 is similar to the third nonlinear prismatic optical element 830. In some embodiments, the fourth nonlinear prismatic optical element 840 includes a first orthogonal ridge 842 and a second orthogonal ridge 844. For example, as shown in FIG. 8, the first orthogonal ridge 842 and the second orthogonal ridge 844 of the fourth nonlinear prismatic optical element 840 are fastened (for example, glued, glued, joined, etc.) to the wedge connection At 843, it forms a wedge angle 845 between the wedge connection 843 and the horizontal cross section parallel to the base of the fourth nonlinear prismatic optical element 840. The divergence angle 847 of the output sub-beams 848a and 848b depends on the wedge angle 845. In some embodiments, the range of the wedge angle 845 and the corresponding divergence angle 847 of the fourth nonlinear prismatic optical element 840 may be about 1° to 45°. For example, the first right-angled triangle orthogonal 842 and the second right triangle orthogonal 844 can form a cube with a wedge angle 845 of 15°.

In some embodiments, the fourth nonlinear prismatic optical element 840 may be a fourth Wollaston prism 840 belonging to the second type, which is configured to have a size smaller than that of the first nonlinear prismatic optical element 810 and The wedge angle (not shown in the figure) of the second nonlinear prismatic optical element 820 and/or the wedge angle 845 and the divergence angle 847 of the wedge angle 825 are, for example, a wedge angle 845 of 15°. The fourth nonlinear prismatic optical element 840 receives the second (+1) first-order sub-beam 846 and separates/generates the second (+1) first-order sub-beam 848a of the first polarization and the second (+1) ) The first-order sub-beam 848b. In some embodiments, for example, the sub-beam 848a may be the linear level (H) of the second (+1) first-order sub-beam 846 The polarization component, and the sub-beam 848b may be the linear vertical (V) polarization component of the second (+1) first-order sub-beam 846, which is orthogonal to the linear horizontal (H) polarization component 848a. In some embodiments, as shown in FIG. 8, the third nonlinear prismatic optical element 830 and the fourth nonlinear prismatic optical element 840 are rotated 90° with respect to each other around the optical axis. In some embodiments, as shown in FIG. 8, the first right-angled triangle orthogonal 鏡842 has an optical axis in the horizontal (H) direction indicated by the horizontal arrow in order to separate/generate the linear horizontal of the input sub-beam 846 The (H) polarization component 848a, and the second right-angled triangle orthogonal beam 844 has an optical axis in the vertical (V) direction to separate/generate the linear vertical (V) polarization component 848b of the input sub-beam 846.

Figure 9 schematically illustrates an exemplary optical system 900 according to some embodiments. According to some examples, the optical system 900 is a 2×2 matrix array 902 of four Wollaston horns 910, 920, 930 and 940 arranged (eg fastened) on the transparent plate 904. The optical system 900 is similar to the optical system 800 of FIG. 8, and FIG. 9 is a top view of the optical system 900.

The optical system 900 includes a first Wollaston optical system 910, a second Wollaston optical system 920, a third Wollaston optical system 930, and a fourth Wollaston optical system 940. In some embodiments, the first Wollaston rod 910 and the second Wollaston rod 920 belong to the first type. For example, the first Wollaston rod 910 and the second Wollaston rod 920 may each have a wedge angle (and a divergence angle) ranging from about 20° to 45°. For example, the first Wollaston rod 910 and the second Wollaston rod 920 may each have a wedge angle (and a divergence angle) ranging from about 40° to 45°. In some embodiments, the third Wollaston rod 930 and the fourth Wollaston rod 940 belong to the second type. For example, the third Wollaston rod 930 and the fourth Wollaston rod 940 may each have a wedge angle (and a divergence angle) ranging from about 1° to 25°. For example, the third Wollaston rod 930 and the fourth Wollaston rod 940 may each have a wedge angle (and a divergence angle) ranging from about 10° to 15°. In some embodiments, as shown in FIG. 9, the first Wollaston horn 910 and The second Wollaston angle 920 is rotated 90° relative to each other around the optical axis, and the third Wollaston angle 930 and the fourth Wollaston angle 940 are rotated 90° relative to each other around the optical axis.

Figure 10 illustrates an exemplary optical system 1000 according to some embodiments of the invention. According to some embodiments, the detection device 700 of FIG. 7 may include the optical system 800 of FIG. 8 or the optical system 900 of FIG. 9. For example, the optical system 750 in FIG. 7 may be the optical system 800 in FIG. 8 or the optical system 900 in FIG. 9. The optical system 800 or the optical system 900 can be positioned near the detector 4 of FIG. 4, and/or the detector 18 of FIG. 5 and/or 6 and/or the detector 740 of FIG. 7, and can be configured To receive the zero-order beam 617a and one-order beam 617b as discussed above in relation to FIG. 6, the zero-order sub-beams 702, 704 and the first-order sub-beams 706, 708 as discussed above in relation to FIG. 7, or as above This article is about the zero-order sub-beams 816 and 826 and the first-order sub-beams 836 and 846 discussed in FIG. 8. According to some embodiments, the optical system 750, the optical system 800, or the optical system 900 may include the optical system 1000 of FIG. 10.

As shown in FIG. 10, the optical system 1000 includes a horizontal (H) polarization component 1002 and a vertical (V) polarization component 1004 separated into an upper diagonal area 1002 and a lower diagonal area 1004 on the detector 1006, respectively. . The detector 1006 may be similar to the detector 4 in FIG. 4, the detector 18 in FIG. 5 and/or FIG. 6 and the detector 740 in FIG. Similar to the optical system 750 of FIG. 7, the optical system 800 of FIG. 8, and the optical system 900 of FIG. 9, the detector 1006 receives and images the first (-0) zero-order sub-beam 1018a of the first polarization and the second polarization The first (-0) zero-order sub-beam 1018b, the second (+0) zero-order sub-beam of the first polarization 1028a and the second (+0) zero-order sub-beam of the second polarization 1028b, the first polarization of the first (-1) The first-order sub-beam 1038a and the second polarization of the first (-1) first-order sub-beam 1038b, and the second (+1) first-order sub-beam 1048a of the first polarization and the second ( +1) First-order sub-beam 1048b. In some embodiments, as shown in FIG. 10, the sub-beams 1018a, 1028a, 1038a, and 1048a may be linear horizontal (H) polarization components, and the sub-beams 1018b, 1028b, 1038b, and 1048b may be linear vertical (V) polarization components, which are orthogonal to the linear horizontal (H) polarization components.

In some embodiments, as shown in FIG. 10, the zero-order sub-beams 1018a, 1018b, 1028a, and 1028b are attributed to the first Wollaston edge of the first type in the optical system 1000, for example, from FIG. 9 The large dispersion angles of the mirror 910 and the second Wollaston 920 (for example, a wedge angle of 45°) are arranged in the outer ring of the detector 1006. In some embodiments, as shown in FIG. 10, the first-order sub-beams 1038a, 1038b, 1048a, and 1048b are attributed to the third Wollaston edge of the second type in the optical system 1000, for example, from the second type in FIG. The small dispersion angle (such as a wedge angle of 15°) of the mirror 930 and the fourth Wollaston ring 940 is arranged in the inner ring on the detector 1006.

In some embodiments, the detector 1006 simultaneously detects zero diffraction order and one diffraction order and the first and second polarizations of each diffraction order 1018a, 1018b, 1028a, 1028b, 1038a, 1038b, 1048a, and 1048b . For example, as shown in FIG. 10, the detector 1006 images the sub-beams 1018a, 1018b, 1028a, 1028b, 1038a, 1038b, 1048a, and 1048b into eight discrete beam spots. In some embodiments, the detector 1006 is a single dark field detector.

In some embodiments, after detecting zero and one diffraction order and the first and second polarizations of each diffraction order, based on one or more diffraction orders (such as 1018a, 1018b, 1028a, 1028b in FIG. 10) , 1038a, 1038b, 1048a and/or 1048b) of the detected first and second polarization adjustment and/or optimization of the parameters of interest of the diffraction target (such as the substrate target 30 in FIG. 5) to improve the metrology system , The accuracy, precision, timing, efficiency, signal-to-noise ratio (S/N) and/or productivity of the lithography system, scatterometer, detection device and/or lithography manufacturing unit. For example, the parameter of interest may be the stacking error between successive layers formed in or on the diffraction target, and/or the critical line width of the developed photosensitive resist. Can be based on individual first and second polarizations (e.g. For the second (+1) first-order sub-beams (H and V of 1048a, 1048b) and/or cross polarization of the first and second polarizations (e.g., the second (+1) first-order sub-beams of the first polarization (H) The amount of 1048a in the second (+1) first-order sub-beam 1048b of the second polarization (V) adjusts (for example, minimizes) the stacking error between successive layers. Additionally or alternatively, for example, the parameter of interest for a 1-D grating may be line width and/or shape. Additionally or alternatively, for example, the parameter of interest for a 2-D grating can be a guide post, the width or length of the via and/or the shape. In some embodiments, the parameter of interest may be an operating parameter of the lithography device, which can be adjusted to improve the accuracy, precision, timing, efficiency, signal-to-noise ratio (S/N) and/or productivity of the lithography device . For example, the operating parameter may be the overlap error. For example, the operating parameter may be the overlay error represented by translation, magnification, rotation, polarization, and/or wafer coordinates.

In some embodiments, after detecting zero and one diffraction order and the first and second polarizations of each diffraction order, based on one or more diffraction orders (such as 1018a, 1018b, 1028a, 1028b in FIG. 10) , 1038a, 1038b, 1048a and/or 1048b) the detected first and second polarization adjustment and/or optimization of the parameters of the lithography device (such as the lithography device 100 or 100') to improve the lithography device Accuracy, precision, timing, efficiency, signal-to-noise ratio (S/N) and/or productivity in the system. For example, the parameters of the lithography device may be the stacking error between successive layers formed in or on the patterned substrate, and/or the critical line width of the developed photosensitive resist. Additionally or alternatively, for example, the parameter of the lithography device may be a recipe step for processing another substrate. Additionally or alternatively, for example, the first and the second detected can be based on one or more diffraction orders (such as 1018a, 1018b, 1028a, 1028b, 1038a, 1038b, 1048a, and/or 1048b in FIG. 10). One or more steps of a two-polarization control manufacturing process, a lithography process, and/or a metrology process.

In some embodiments, the first and second polarizations of one or more diffraction orders can be studied by the detector 18 and/or the processing unit PU. In some embodiments, the horizontal (H) polarization can be studied The cross polarization of the component and the vertical (V) polarization component. For example, it is possible to measure how much of the horizontal (H) polarization component for one or more diffraction orders has leaked into the vertical (V) polarization component, and vice versa. In some embodiments, for some diffractive targets, the strength/intensity of each polarization (H or V) can be studied. For example, the amount of horizontal (H) polarization for some targets (such as the shape of a horizontal line) can be greater than the amount of vertical (V) polarization, and the cross polarization (such as how much H has leaked into V) can be compared to determine a specific target, substrate And/or the better accuracy and/or precision of the concerned parameters of the lithography device.

In some embodiments, the optical system of the embodiments of the present invention can be configured to separate the H and V polarizations of the unpolarized light beams and to image both the H and V polarized light beams at a common focal plane (such as a pupil plane) To a single detector (such as a dark field sensor). Additionally or alternatively, the optical system of the embodiment of the present invention can minimize chromatic aberration by making the optical system with one or more nonlinear prismatic optical elements act as flat plates in both the H and V polarization beam paths ( For example, lateral chromatic aberration).

The following items can be used to further describe the embodiments:

1. A detection device comprising: an optical system comprising a non-linear prismatic optical element and configured to receive zero and one diffraction order beams reflected from a diffraction target and to separate each diffraction order The first and second polarizations of the beam; and a detector configured to simultaneously detect the first and second polarizations of each of the zero and one diffraction order beams.

2. The detection device of clause 1, wherein the optical system is located at a pupil plane of the detection device.

3. The detection device of clause 1, wherein the nonlinear prismatic optical element is birefringent and It is configured to separate normal rays and abnormal rays from each of the zero and one diffraction order beams.

4. The detection device of clause 1, wherein: the first polarization of each of the zero and one diffraction order light beams is a horizontal polarization component, and each of the zero and one diffraction order light beams The second polarization of one is a vertical polarization component, which is orthogonal to the horizontal polarization component.

5. The detection device of clause 1, wherein the optical system further includes a plurality of nonlinear prismatic optical elements.

6. The detection device according to Clause 5, wherein the plurality of nonlinear prismatic optical elements include a plurality of Wollaston horns.

7. The detection device of clause 6, wherein the plurality of Wollaston horns include: two Wollaston horns of the first type, each having a first wedge angle and a corresponding first divergence angle , The two first-type Wollaston horns are rotated 90° relative to each other; and two second-type Wollaston horns, each having a second polarization wedge angle and a corresponding second divergence angle , Wherein the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle, and the two second-type Wollaston horns are rotated by 90° relative to each other.

8. A lithography device for measuring stacks based on micro-diffraction, comprising: a first illuminating optical system configured to illuminate a diffraction pattern; a projection optical system, which is assembled State to project an image of the diffraction pattern onto a substrate; and a scatterometer, which is configured to determine a parameter of the lithography device, the scatterometer includes: a second illuminating optical system, which is assembled State to deliver at least one radiation beam; an objective optical system configured to focus the at least one radiation beam to the base Board; and a detection device configured to detect a reflected radiation beam from the substrate, including: an optical system including a nonlinear prismatic optical element, and configured to receive self-diffraction The zero and one diffraction order beams reflected by the target and separate the first and second polarizations of each diffraction order beam; and a detector configured to simultaneously detect the zero and one diffraction order beams Each of the first and second polarization.

9. The lithography device according to Clause 8, wherein the nonlinear prismatic optical element is selected from the group consisting of: a birefringent optical element, a Wollaston plate, a Nomarski plate , A Senna monk, a Loh-Hungary, a Grand-Thompson, and a Grand-Foucault.

10. The lithography device according to clause 8, wherein the optical system includes a neutral density filter configured to normalize a zero winding with respect to an intensity of a diffraction order The intensity of one of the firing steps.

11. The lithography device of clause 8, wherein the optical system is located at a pupil plane of the detection device, and the detector is a single dark field detector.

12. The lithography device of clause 8, wherein: the first polarization of each of the zero and one diffraction order light beams is a horizontal polarization component, and one of the zero and one diffraction order light beams The second polarization of each is a vertical polarization component, which is orthogonal to the horizontal polarization component.

13. The lithography device of clause 8, wherein the optical system further includes a plurality of nonlinearities Prismatic optics.

14. The lithography device according to clause 13, wherein the plurality of nonlinear prismatic optical elements include a plurality of Wollaston horns.

15. The lithography device according to Clause 14, wherein the plurality of Wollaston horns include: two Wollaston horns of the first type, each having a first wedge angle and a corresponding first divergence Angle, the two first-type Wollaston horns are rotated 90° relative to each other; and two second-type Wollaston horns, each having a second polarization wedge angle and a corresponding second divergence Angles, wherein the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle, and the two second-type Wollaston horns are rotated by 90° relative to each other.

16. The lithography device of clause 14, wherein the plurality of Wollaston horns are arranged on a transparent plate in a 2×2 matrix array, and are configured to separately receive the first and second zero windings The second order sub-beams and the first and second diffraction order sub-beams.

17. The lithography device of clause 16, wherein a horizontal polarization component for each of the first and second zero-diffraction-order sub-beams and the first and second diffraction-order sub-beams And one of the vertical polarization components orthogonal to the horizontal polarization component is separated by the corresponding plurality of Wollaston's beams, and is imaged into eight discrete beam spots by the detector.

18. A method for measuring the superposition based on micro-diffraction, which comprises: zero and a diffraction order reflected from a diffraction target by an optical system including a nonlinear prismatic optical element The first and second polarizations of the two beams are separated; the zero and one diffraction order and the first and second polarization of each diffraction order are detected simultaneously by a detector; and based on one or more diffraction orders The detected first and second polarizations adjust an operating parameter of a lithography device to improve the accuracy or precision of the lithography device.

19. The method of clause 18, further comprising: separately separating the first and second zero diffraction order sub-beams and the first and second first diffraction order sub-beams; and isolating the first and second diffraction order sub-beams; A horizontal polarization component of each of the zero diffraction order sub-beam and the first and second diffraction order sub-beams and a vertical polarization component orthogonal to the horizontal polarization component.

20. The method of clause 19, further comprising imaging the horizontal and vertical polarization components of each zero and one diffraction order sub-beams into eight discrete beam spots on a single dark field detector.

Although the use of lithography devices in IC manufacturing can be specifically referred to herein, it should be understood that the lithography devices described herein may have other applications, such as manufacturing integrated optical systems and guiding magnetic domain memory. Leads and detects patterns, flat panel displays, LCDs, thin film magnetic heads, etc. Those familiar with this technology should understand that in the context of these alternative applications, any use of the term "wafer" or "die" in this article can be regarded as synonymous with the more general term "substrate" or "target part" respectively. . The mentioned herein can be processed before or after exposure in, for example, a coating and development system unit (usually a tool for applying a resist layer to a substrate and developing the exposed resist), a metrology unit, and/or a detection unit Substrate. When applicable, the disclosure in this article can be applied to such and other substrate processing tools. In addition, the substrate can be processed more than once, for example to produce a multilayer IC, so that the term substrate used herein can also refer to a substrate that already contains multiple processed layers.

Although the above can specifically refer to the use of the embodiments of the present invention in the context of optical lithography, it should be understood that the present invention can be used in other applications (such as imprint lithography), and where the context of the content allows Not limited to optical lithography. In imprint lithography, the topography in the patterned device defines the pattern produced on the substrate. The configuration of the patterned device Press into the resist layer supplied to the substrate. On the substrate, the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterned device is removed from the resist, leaving a pattern in it.

It should be understood that the terms or terms in this text are for the purpose of description rather than limitation, so that the terms or terms in this specification should be interpreted by those familiar with the relevant technology in view of the teachings in this text.

The term "substrate" as used herein describes the material to which the material layer is added. In some embodiments, the substrate itself can be patterned, and the material added on the top of the substrate can also be patterned, or the material added on the top of the substrate can remain unpatterned.

The embodiments of the present invention can be implemented by hardware, firmware, software, or any combination thereof. The embodiments of the present invention can also be implemented as instructions stored on a machine-readable medium, and these instructions can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (such as a computing device). For example, machine-readable media may include read-only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, and acoustic formats Or other forms of propagation signals, and others. In addition, firmware, software, routines, and/or commands may be described herein as performing certain actions. However, it should be understood that such descriptions are only for convenience, and these actions are actually caused by computing devices, processors, controllers, or other devices that execute firmware, software, routines, instructions, etc.

The following examples illustrate rather than limit embodiments of the present invention. Other suitable modifications and adaptations of multiple conditions and parameters that are generally encountered in the field and will be obvious to those familiar with the related art are within the spirit and scope of the present invention.

Although the device and/or system according to the present invention may be specifically referred to herein in It is used in the manufacture of IC, but it should be clearly understood that such devices and/or systems have many other possible applications. For example, it can be used to manufacture integrated optical systems, guide and detect patterns for magnetic domain memory, LCD panels, thin-film magnetic heads, etc. Those familiar with this technology will understand that, in the context of such alternative applications, any use of the terms "reduced mask", "wafer" or "die" in this article should be considered as the more general term " Replacement of "mask", "substrate" and "target part".

Although specific embodiments of the present invention have been described above, it should be understood that the present invention can be practiced in other ways than those described. This description is not intended to limit the invention.

It should be understood that the [Implementation Mode] chapter rather than the [Invention Content] and [Chinese Abstract of Invention] chapters are intended to interpret the scope of the patent application. The sections of [Summary of the Invention] and [Abstract of Chinese Invention] may describe one or more but not all exemplary embodiments of the present invention as expected by the present inventor, and therefore are not intended to limit the present invention and the accompanying patents in any way Scope.

The present invention has been described above with reference to the function building blocks that illustrate the implementation of specific functions and the relationship between these functions. For ease of description, this article has arbitrarily defined the boundaries of these functional building blocks. As long as the specified functions are properly performed and the relationship between these functions, alternative boundaries can be defined.

The foregoing description of the specific embodiments will therefore fully reveal the general nature of the present invention: without departing from the general concept of the present invention, others can easily apply the knowledge known to those skilled in the art for various applications. Modify and/or adapt these specific embodiments without undue experimentation. Therefore, based on the teachings and guidance presented herein, these adaptations and modifications are intended to be within the meaning and scope of equivalents of the disclosed embodiments.

The breadth and scope of the present invention should not be limited by any of the above-mentioned exemplary embodiments, but should only be defined according to the scope of the following patent applications and their equivalents.

700: detection device

702: First (-0) zero-order sub-beam/first (-0) zero-order input sub-beam/zero-order diffracted beam

704: second (+0) zero-order sub-beam/second (+0) zero-order input sub-beam/zero-order diffracted beam

706: First (-1) first-order sub-beam/first (-1) first-order input sub-beam/first-order diffracted beam

708: second (+1) first-order sub-beam/second (+1) first-order input sub-beam/first-order diffracted beam

710: The first nonlinear prismatic optics

711: wedge connection

712: The first right-angled triangle orthogonal 鏡

713: Wedge Angle

714: Second Right Triangle Orthogonal 鏡

715a: Divergence angle

715b: Divergence angle

716a: the first (-0) zero-order output sub-beam of the first polarization/linear horizontal (H) polarization component

716b: The first (-0) zero-order output sub-beam of the second polarization

718a: The second (+0) zero-order output sub-beam of the first polarization/linear horizontal (H) polarization component

718b: The second (+0) zero-order output sub-beam of the second polarization

720: Second nonlinear prismatic optics

721: wedge connection

723: Wedge Angle

724: The second right-angled triangle orthogonal 鏡

725a: divergence angle

725b: divergence angle

726a: the first (-1) first-order output sub-beam of the first polarization/linear horizontal (H) polarization component

726b: The first (-1) first-order output sub-beam of the second polarization

728a: the second (+1) first-order output sub-beam of the first polarization/linear horizontal (H) polarization component

728b: The second (+1) first-order output sub-beam of the second polarization

730: lens system

740: Detector

750: optical system

F: Focal length

ND: Neutral Density Filter

Claims (20)

A detection device, which includes: An optical system including a non-linear prismatic optical element and configured to receive zero and one diffraction order beams reflected from a diffraction target and to separate the first and second polarizations of each diffraction order beam; and A detector configured to simultaneously detect the first and second polarizations of each of the zero and one diffraction order beams. Such as the detection device of claim 1, wherein the optical system is located at a pupil plane of the detection device. Such as the detection device of claim 1, wherein the nonlinear prismatic optical element is birefringent and configured to separate normal rays and abnormal rays from each of the zero and one diffraction order beams. Such as the detection device of claim 1, where: The first polarization of each of the zero and one diffraction order light beams is a horizontal polarization component, and The second polarization of each of the zero and one diffraction order beams is a vertical polarization component, which is orthogonal to the horizontal polarization component. The detection device of claim 1, wherein the optical system further includes a plurality of nonlinear prismatic optical elements. Such as the detection device of claim 5, wherein the plurality of nonlinear prismatic optical elements include a plurality of Wollaston horns. Such as the detection device of claim 6, wherein the plurality of Wollaston horns include: Two first-type Wollaston horns, each having a first wedge angle and a corresponding first divergence angle, the two first-type Wollaston horns are rotated 90° relative to each other; and Two second-type Wollaston horns, each having a second polarization wedge angle and a corresponding second divergence angle, wherein the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle The second divergence angle, the two second-type Wollaston horns are rotated 90° with respect to each other. A lithography device for measuring the superposition based on micro-diffraction, which includes: A first illumination optical system configured to illuminate a diffraction pattern; A projection optical system configured to project an image of the diffraction pattern onto a substrate; and A scatterometer configured to determine a parameter of the lithography device, the scatterometer comprising: A second illumination optical system configured to deliver at least one radiation beam; An objective optical system configured to focus the at least one radiation beam onto the substrate; and A detection device configured to detect a reflected radiation beam from one of the substrates, which includes: An optical system including a non-linear prismatic optical element and configured to receive zero and one diffraction order beams reflected from a diffraction target and to separate the first and second polarizations of each diffraction order beam; and A detector configured to simultaneously detect the first and second polarizations of each of the zero and one diffraction order beams. Such as the lithography device of claim 8, wherein the nonlinear prism-shaped optical element is selected from the group consisting of: a birefringent optical element, a Wollaston prism, and a Nomarski prism Mirror, a Sénarmont porch, a Rochon porch, a Glan-Thompson porch, and a Glan-Foucault porch. The lithography device of claim 8, wherein the optical system includes a neutral density filter configured to normalize a zero diffraction order with respect to an intensity of a diffraction order One intensity. Such as the lithography device of claim 8, wherein the optical system is at a pupil plane of the detecting device, and the detector is a single dark field detector. Such as the lithography device of claim 8, in which: The first polarization of each of the zero and one diffraction order light beams is a horizontal polarization component, and The second polarization of each of the zero and one diffraction order beams is a vertical polarization component, which is orthogonal to the horizontal polarization component. The lithography device of claim 8, wherein the optical system further includes a plurality of nonlinear prismatic optical elements. Such as the lithography device of claim 13, wherein the plurality of nonlinear prismatic optical elements include a plurality of Wollaston horns. Such as the lithography device of claim 14, in which the plurality of Wollaston horns include: Two first-type Wollaston horns, each having a first wedge angle and a corresponding first divergence angle, the two first-type Wollaston horns are rotated 90° relative to each other; and Two second-type Wollaston horns, each having a second polarization wedge angle and a corresponding second divergence angle, wherein the first wedge angle and the first divergence angle are greater than the second wedge angle and the second divergence angle The second divergence angle, the two second-type Wollaston horns are rotated 90° with respect to each other. Such as the lithography device of claim 14, wherein the plurality of Wollaston horns are arranged on a transparent plate in a 2×2 matrix array, and are configured to separately receive the first and second zero diffraction orders The sub-beams and the first and second diffraction order sub-beams. For example, the lithography device of claim 16, wherein the first and second zero-diffraction-order sub-beams and each of the first and second-diffraction-order sub-beams have a horizontal polarization component and a positive One of the vertical polarization components intersecting the horizontal polarization component is separated by the corresponding plurality of Wollaston horns, and is imaged into eight discrete beam spots by the detector. A method for measuring the superposition based on micro-diffraction, which includes: Separating the first and second polarizations of the zero and one diffraction order beams reflected from a diffraction target by an optical system including a nonlinear prismatic optical element; Simultaneous detection of zero and one diffraction order and the first and second polarization of each diffraction order by a detector; and Based on the detected first and second polarizations of one or more diffraction orders, an operating parameter of a lithography device is adjusted to improve the accuracy or precision of the lithography device. Such as the method of claim 18, further including: Separate the first and second zero diffraction order sub-beams and the first and second first diffraction order sub-beams; and Isolating a horizontal polarization component for each of the first and second zero-diffraction-order sub-beams and the first and second diffraction-order sub-beams and a vertical perpendicular to the horizontal polarization component Straight polarization component. Such as the method of claim 19, which further comprises imaging the horizontal and vertical polarization components of each zero and one diffraction order sub-beams into eight discrete beam spots on a single dark field detector.

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